On frost fighting.
Photo by Sam Tasso
Spring in Bannockburn is often a wild ride.
It’s a fragile time in the vineyard. At the start of spring, we see bud budburst — the beginnings of what will become our future crop. During spring, flower clusters gradually unfurl from the new shoots, and at the end of the spring, they flower. Those flowers then become our future fruit.
As you can imagine, damage to the buds and flowers in spring can be catastrophic to the future fruit crop. In severe cases, a winery could lose 100% of their crop to frost damage. There’s no worse time to experience cold conditions.
That’s why, a few weeks ago when that unseasonable cold snap hit, we were less focused on the picturesque snowy views and more worried about our vines.
Winemaking amongst the elements in Bannockburn, Central Otago is no easy task. Thankfully, we do have some tools at our disposal when spring frosts hit.
Windmachines
They’re not cheap, but they’re effective. If you can have a windmachine on your vineyard, you can make sure the air is moving enough to stop frost from settling on your vines. The only issue? They are LOUD — keep the neighbourhood up all night loud. Whenever the mercury drops to 0.5 degrees celsius, the windmachines kick into gear. An unwelcome sound with a very welcome result.
Great pic from our neighbours @burncottagevineyard
Water
It might seem counterintuitive, but if you can encase your buds in a water droplet at the moment when the frost hits, then you end up with a frozen water droplet, not a frozen blossom. As long as the flower bud is perfectly encased in a protective layer of ice, the harsh bite of frost can’t get to it.
Helicopters
If you don’t have a windmachine, you can always call in a helicopter, but it’s not bloody cheap! It’s also particularly dangerous if you have large poplar trees by the vineyard. Chopper pilots use a green and red light system to know where to fly over — temperature readings will alter the light. A red light means to stay put, hovering over the site. The moment the light turns green, it means the air is dispersed and the pilot is okay to move to another section of the vineyard.
The last few weeks have seen frosts so severe that green lights have turned back to red the moment a pilot starts to move on. That means a high cost for protecting the fruit.
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You will be happy to hear our vines have made it through that brutal cold snap. Fingers crossed it’s the last thing 2020 throws at us, but given the year so far, we doubt it.
Next time you drink a glass of wine from Central Otago, remember it’s not just the grapes in the glass that make each vintage special, but it’s also the team of people who help us keep the wheels (or windmachines) turning in the middle of the night.
Photo by Sam Tasso
Photo by Sam Tasso